Inventive concepts relate to semiconductor devices and a methods of driving the same, and more particularly, to a non-volatile memory device using a resistive memory material film and a method of driving the non-volatile memory device.
Recently, demands for portable digital appliances such as digital cameras, MPEG (Moving Picture Experts Group) layer 3 (MP3) players, personal digital assistants (PDAs), and mobile phones have increased, and thus, the markets of non-volatile memories are rapidly expanding. Flash memories of high density, which have low fabrication costs per bit, are widely used as programmable non-volatile memories. However, flash memory devices require relatively large transistors for performing a hot-carrier injection operation required in programming, and also require thick tunneling oxide layers that may bear high internal voltage for ensuring data storage for 10 years or longer. Thus, there is a limitation in scaling the flash memories. Recently, since flash memories have reached a lower limit in scaling, resistance random access memories (ReRAMs) using a resistive memory material are drawing attention as non-volatile memories that may substitute for the flash memories.
Since the resistive memory material has a bi-stable resistance state, in which resistance status may reciprocally vary depending on electric pulses applied to the resistive memory material, the ReRAM may operate without using a transistor, and thus, may be finely fabricated to a cell size of 10 nm or less.
The ReRAM includes wires crossing over each other and cells that are formed on intersections between the wires and that include resistive memory materials. However, when the cells are formed in such a simple structure, there may be an error in a reading operation because signals may be detected from neighboring cells. To address this problem, a rectifying device such as a diode or a switching device such as a transistor is additionally formed in the cell structure.